Grinding and polishing knives



UNITED STATES PATENT OFFICE.

JAMES DODGE, OF WATE-RFOBD, NEW YORK.

GRINDING AND POLISHING KNIVES.

Specification forming part of Letters Patent No. 21,746, dated October12, 18581; Ressued May 31,

1859, No. 733. i

To @ZZ 'whom t may concern.'

Be it known that I, JAMES DODGE, of Waterford, Saratoga county, State ofNew York, have invented a new and useful Method for Grinding andPolishing Knives or other Articles of Cutlery and Tools and I declarethe following specification, with the drawings hereto attached as partof the same, to be a full and perfect description thereof.

Figure l is a perspective view of the machine I use. Figs. 2 and 3 arediagrams illustrating the operation of the machine.

Upon a strong frame A, A, A, A, a grindstone B is mounted on a shaft oraXis a, a, properly fitted with journals and boxes and band wheels orgearing to revolve it with requisite velocity. Upon the same frameanother shaft ZJ, b, is arranged, with suitable journals and boxes,lying parallel with shaft a, t To this shaft is attached a cylinder C,arranged to revolve in the same direction with the grindstone B, bymeans of the bandwheel D with its band E passing around drum G on shafta` (or by any other suitable gearing) by which the relative movement ofthe stone to the cylinder can be adjusted. This cylinder is intended tohold and carry the knives, or other articles to be ground by the stone.

Upon the margin of the cylinder a flange H projects having suitableopenings e, c, through it, at the surface of the cylinder, for theinsertion, in the case of knife blades and similar articles, of theirstems, to be confined with set screws tapped through the flange so as tolie properly upon the face of the cylinder to receive the action of thegrindstone.

In order to adjust the articles with more eXactness and certainty, thereis'sunk into the face of the cylinder a matrix or impression of thearticle as prepared for the grinding. This will prevent the article fromsliding along the surface of the wheel when under th-e attrition of thegrindstone.

The grinding being effected by the revolution of the article on a curve,the result will be, if it be held immovably on the face of the cylinderthat the ground surface will be a convex of the curve or arc of thecylinder subtended by the article to be ground. The convexity of theform can be diminished, and the surface can be ground flat by giving thecross section of the matrix fr, y, an increasing convex shape, as shownin Fig. l

2 vwhere by sinking its outer edges f, f, equal to the sine g, of thecurve, from f to f, and allowing the article being ground to rock on itscurve, as it passes under the stone a iat surface is produced. If theconvexity of the bottom of the matrix be increased, (see Fig. 3,) thesurface may be ground concave, like a razor blade.

For certain purposes it becomes convenient not to change the cylinderwith every change of article to be ground. In that case I have thematrices formed upon segments of metal fitted to the curve of thecylinder so as to be affixed or removed without disturbing the cylinder.

In order to allow of the employment of grindstones of moderate width,when articles longer than that width are to be ground, the shaft of thecylinder is extended as shown at I so as to permit the cylinder, whichmust be as wide as the article to be ground is long to be moved over thesurface of the stone, or vice versa, the stone may be arranged to bemoved over the surface of the cylinder.

In order to allow the proper play of the article in hand to form thedesired surface flat or concave, the stem of the blade can be fittedinto movable sockets, kept in place by the set screws f, f, so as to beheld down in the matrix, and yet turn sufficiently for grindingpurposes.

For the polishing process, an emery wheel, or wheel covered withsuitable polishing material is to be substituted for the grindstone.

I claiml. The method of grinding and polishing articles and formingtheir surfaces upon a revolving grindstone or polishing wheel byattaching them to a drum or cylinder which is made to revolve in thesame direction with the stone or wheel and with velocity adjustablethereto, substantially as above set forth, in the within specification.

2. I further claim the method of attaching and supporting upon a curvedsurface the article to be ground, so as to permit it to rock thereon,thereby shaping the surface when formed either fiat, concave or convex,substantially as above set forth.

JAMES DODGE.

Witnesses z E. J. MILLER, RICHD. VARICK DE WITT.

[Fnis'r PRINTED 1911.]

